Today East Asia harbors many “relict” plant species whose ranges were much larger during the Paleogene-Neogene and earlier. The ecological and climatic conditions suitable for these relict species have not been identified. Here, we map the abundance and distribution patterns of relict species, showing high abundance in the humid subtropical/warm-temperate forest regions. We further use Ecological Niche Modeling to show that these patterns align with maps of climate refugia, and we predict species’ chances of persistence given the future climatic changes expected for East Asia. By 2070, potentially suitable areas with high richness of relict species will decrease, although the areas as a whole will probably expand. We identify areas in southwestern China and northern Vietnam as long-term climatically stable refugia likely to preserve ancient lineages, highlighting areas that could be prioritized for conservation of such species.

ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plotbased ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science.

Thismia is a genus of > 80 mycoheterotrophic species characterized by a peculiar appearance and complex floral morphology. A significant proportion of the species and morphological diversity of Thismia has only been uncovered in the past two decades, and new discoveries continue to be made. Given that many new data have recently become available, and the most comprehensive taxonomic revision of the genus from 1938 addresses less than half of the currently known species, previous hypotheses for species relationships and infrageneric taxonomic classification in Thismia was in need of review. Extensive molecular phylogenetic studies of Thismia at the genus level have never been presented. We investigate the phylogenetic relationships of 41 species (and one variety) of Thismia from the Old World. Our study comprises 68 specimens (for 28 of which the data were newly generated), including outgroup taxa broadly representing Thismiaceae (= Burmanniaceae p.p. sensuAPG IV, 2016), and is based on two nuclear and one mitochondrial marker. We use maximum likelihood and Bayesian inference to infer relationships among the taxa. We also constructed a morphological dataset of 12 mostly floral characters, comparing these characters to hypotheses based on molecular evidence to identify putative synapomorphies for major clades and to discuss hypotheses regarding the evolution of structural traits in the genus. Our analyses indicate that the majority of currently accepted infrageneric taxa of Thismia are polyphyletic. We find support for the monophyly of the Old World group, in which we recognize five well-supported lineages (clades); the only New World species studied appears to be related to the Neotropical genus Tiputinia. Ancestral state reconstructions demonstrate that the evolution of most morphological characters was homoplastic, but we identify characters that provide each of the five clades of Old World Thismia with a unique morphological description. The geographical distribution of the species under study is also shown to be consistent with the major clades. Our investigation provides a phylogenetic basis for the development of a novel sectional classification of Thismia reflecting morphological and geographical traits.

Aristolochia subgenus Siphisia comprises about 70 species, with a disjunct East-and South Asian to North-and Central American distribution. Here we describe and illustrate three new species of Aristolochia subgenus Siphisia from Vietnam: Aristolochia faviogonzalezii, A. tonkinensis, and A. tadungensis. The first two species are found in northern Vietnam while the latter occurs in southern Vietnam. Diagnostic characters distinguish the new species from their morphologically close relatives. Their distribution, ecology, phenology, ethnobotany, and conservation status are presented as well. In addition, three species are newly reported for the flora of Vietnam that were until now restricted to China, namely A. fangchi, A. hainanensis, and A. utriformis. An identification key to all Asian species of Aristolochia subgenus Siphisia is provided.

1We present the first crossdated tree ring record from central Vietnam, derived from the growth 2 rings of the rare cypress Fokienia hodginsii from the mountains of Quang Nam Province near the 3 Laos border. The Quang Nam Fokienia hodginsii time series (QNFH), based on the crossdated 4 sequences of 71 increment core samples from 37 mature trees, is the third published 5 dendrochronological record from this species. The record extends 667 years from AD 1347 to 6 2013 and exhibits a mean series intercorrelation of 0.526, similarly significant with the first two 7published Fokienia hodginsii records: 0.474 for Mu Cang Chai (MCFH) and 0.578 for Bidoup -8Nui Ba National Park (BDFH) in the north and south of Vietnam, respectively. The Expressed 9Population Signal (EPS) for the QNFH record exceeds the generally accepted threshold of 0.85 10 back to AD 1567, but remains above 0.8 back to 1550. Similar to the MCFH and BDFH records, 11 QNFH expresses statistically significant linkages to regional hydroclimate metrics and the El 12 Niño-Southern Oscillation (ENSO). Here we present a reconstruction of the Standardized 13Precipitation Evapotranspiration Index (SPEI) for the month of April, averaged over a large 14 region of Southeast Asia. As with prior studies we demonstrate that cool phase (La Niña) and 15 warm phase (El Niño) events are linked to regional wet and dry conditions, respectively, with 16 linkages to modulation of the surface water temperature over the adjacent sea to the east of 17Vietnam as well as the Indian Ocean. A late 18 th century megadrought that is expressed widely 18 across South and Southeast Asia, and notably from the MCFH and BDFH records described 19 above, is not as pronounced in Central Vietnam and we explore the reasons why. 20 21